Epithelial neoplasms of the vermiform appendix (exclusive of carcinoid). II. Cystadenomas, papillary adenomas, and adenomatous polyps of the appendix.

Forty-two cases of benign epithelial neoplasms of the appendix gleaned from the files of the Laboratory of Surgical Pathology, Columbia University, were studied. The majority were associated with dilatation of the appendix, or "mucocele." Conversely only 50% of all cystically dilated appendices examined had definite underlying adenomatous changes. Thus it is important to distinguish between cystic neoplasms (cystadenomas) and non-neoplastic retention cysts of the appendix. The most frequently found benign epithelial neoplasms were papillary adenomas. Even in the presence of atypia we labeled them benign. Appendectomy is usually adequate treatment for all adenomatous lesions occurring in the appendix. Almost a quarter of the cases reviewed were found to have synchronous or metachronous neoplasms elsewhere in the colon, while several patients harbored multiple colonic neoplasms in addition to the appendiceal adenomas. Thus a patient with an adenomatous lesion of the appendix should undergo a systematic search for other colonic lesions.